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- Table of Contents
SLPI / Antileukoproteinase · Western blot design guide
Design a Western Blot for SLPI
Real validated SLPI Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-SLPI WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Evidence assembled September 2026 · For research use; verify linked source records and product datasheet before use
SLPI Western Blot Experimental Design Guide
Expected bands, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | ~14.3 kDa | |
| Gel | 15% (standard starting point) | |
| Positive control | Cervix (IHC candidate; verify WB) +4 more | |
| Negative control | Adipose tissue (IHC candidate; verify WB) |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Cleaved | |
| Caveat | Secreted protein | |
| Gene-set association | MSigDB Hallmark membership | |
| Isoform | 1 isoform(s) |
Section 1
Real Curated SLPI Western Blot Protocols
The A01682 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | Daudi cell lysate (catalog A01682) |
| Gel % | 15% (standard starting point) |
| Load | 20–30 µg total protein per lane; optimize for abundance (standard starting point) |
| Transfer | Short semi-dry transfer; verify retention (standard starting point) |
| Membrane | 0.2 µm PVDF (standard starting point) |
| Blocking | 5% milk or 5% BSA in TBST (standard starting point) |
| Primary antibody | A01682 · (A) 1 and (B) 2 μg/mL (catalog A01682) |
| Primary incubation | Overnight at 4 °C (standard starting point) |
| Secondary antibody | Species-matched HRP conjugate at validated dilution (standard starting point) |
| Secondary incubation | 1 h at room temperature (standard starting point) |
| Wash | 3 × 5 min in TBST (standard starting point) |
| Detection | ECL; bracket exposures to avoid saturation (standard starting point) |
Section 2
What Is the Expected SLPI Western Blot Band Size?
SLPI has a predicted 14.3 kDa precursor; signal-peptide cleavage may yield a smaller mature band, but no migration shift is demonstrated.
| Band near 14.3 kDa | Consistent with the predicted SLPI precursor; confirm its identity. |
| Band below 14.3 kDa | Could reflect removal of the 25-residue signal peptide; confirm its identity. |
| Faint band in whole-cell lysate | Consistent with SLPI secretion limiting intracellular abundance. |
| No band in whole-cell lysate | SLPI may have been secreted into the medium. |
💡Expected SLPI appearanceThe predicted SLPI precursor is 14.3 kDa; signal-peptide cleavage may yield a smaller mature band, but no empirical migration value is supplied, so confirm candidate bands with identity controls.
| Predicted precursor mass | Sets the full-length reference at 14.3 kDa. |
| Signal peptide at residues 1–25 | Its removal can yield a smaller mature protein. |
| Uncleaved signal-bearing precursor | Retains the sequence included in the 14.3 kDa prediction. |
| Secreted mature SLPI | May migrate below the predicted precursor after signal-peptide cleavage; its apparent mass is unknown. |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | SLPI is secreted. | Check conditioned medium alongside lysate. |
| Band lower than expected | The signal peptide may have been cleaved. | Compare secreted and cellular samples and verify band identity. |
| Weak or no signal | The sampled fraction may contain little secreted SLPI. | Check conditioned medium and include a positive control. |
| Multiple bands | Band identities are unresolved; only one isoform is listed. | Use an independent antibody or SLPI depletion to identify the specific band. |
| Band higher than expected | The supplied features do not establish a higher-mass SLPI species. | Verify specificity with an independent antibody or SLPI depletion. |
Experiment evidence
Western blot images showing SLPI band
A01682 · SLPI
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for SLPI Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for SLPI in Western blot, you can use cervix tissue, which shows high HPA expression.
Positive control: Cervix (IHC candidate; verify WB)
Negative control: Adipose tissue (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.
⚠️Feasibility: SLPI is secreted, so conditioned medium may give a clearer signal than whole-cell lysate.
HPA tissue expression evidence for SLPI
Comprehensive Human Protein Atlas IHC scoring per tissue. Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Higher expression tissues · candidate positive controls from IHC
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Cervix | glandular cells | High | Protein (IHC) | HPA → |
| Nasopharynx | goblet cells | High | Protein (IHC) | HPA → |
| Bronchus | respiratory epithelial cells | Medium | Protein (IHC) | HPA → |
| Fallopian tube | ciliated cells (tip of cilia) | Medium | Protein (IHC) | HPA → |
| Kidney | cells in tubules | Medium | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | adipocytes | Not detected | Protein (IHC) | HPA → |
| Adrenal gland | glandular cells | Not detected | Protein (IHC) | HPA → |
| Appendix | endocrine cells | Not detected | Protein (IHC) | HPA → |
| Bone marrow | hematopoietic cells | Not detected | Protein (IHC) | HPA → |
| Breast | adipocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SLPI Western Blot Tips
Deeper troubleshooting and optimisation questions for SLPI, answered from its protein features.
How should SLPI band migration be interpreted?
Band shift · Use the separately labelled calculated mass and catalog-observed evidence above. A sequence annotation does not establish an observed migration shift. Verify target identity with orthogonal controls.
Are alternative SLPI isoforms expected to create multiple bands?
Isoforms · Only one isoform is listed, with no alternative sequence. Do not assign multiple bands to annotated SLPI isoforms on this evidence; assess other explanations for any additional bands.
Do listed modifications explain a heavier SLPI band?
PTM · No glycosylation sites or modified residues are listed. These features provide no specific modification to assign to a heavier band. Check the sample conditions and band identity before interpreting it as modified SLPI.
Does this guide establish induction of SLPI?
Induction · No general induction response is established by this guide. A pathway or gene-set association is not evidence of induction in a particular specimen. Verify the relevant treatment and control in a target-specific experiment.
How should transfer be checked for SLPI?
Transfer · Standard workflow guidance: verify transfer efficiency for the intended target size before interpreting a weak signal. Use total-protein assessment and optimize transfer for the membrane, gel and apparatus; the labelled catalog values take precedence.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A01682 datasheet where specified. Otherwise compare 5% milk or 5% BSA in TBST; for a phospho-specific assay start with BSA. Optimize background and specific signal with matched controls.
How should SLPI be quantified?
Quantitation · Standard workflow guidance: quantify only a validated target band within the linear exposure range. Use consistent sample preparation and loading, retain biological replicates, and avoid interpreting saturation or loading differences as regulation.
Why might SLPI migrate below its predicted 14.3 kDa?
Interpretation · The 14.3 kDa prediction includes the 1..25 signal peptide. Cleavage during secretion would reduce the protein's mass, but no observed band size is supplied. Signal peptide cleavage alone does not establish where SLPI will migrate on a blot.
SLPI has eight disulfide bonds. Compare reducing and nonreducing preparations if its band pattern changes with sample treatment. Different migration could reflect altered disulfide bonding, but the listed features do not establish a specific band shift.
SLPI is annotated as secreted. For comparisons, use the same sample fraction across conditions and account for differences in the amount of material collected. A change in a cellular fraction alone may not represent a change in total SLPI.
SLPI interacts with GRN, but that interaction does not establish that a complex survives Western blot preparation. Treat a high-mass band as unassigned until its identity is checked; the supplied features alone cannot identify it as an SLPI–GRN complex.
SLPI has eight disulfide bonds. Compare reducing and nonreducing preparations if its band pattern changes with sample treatment. Different migration could reflect altered disulfide bonding, but the listed features do not establish a specific band shift.
SLPI is annotated as secreted. For comparisons, use the same sample fraction across conditions and account for differences in the amount of material collected. A change in a cellular fraction alone may not represent a change in total SLPI.
SLPI interacts with GRN, but that interaction does not establish that a complex survives Western blot preparation. Treat a high-mass band as unassigned until its identity is checked; the supplied features alone cannot identify it as an SLPI–GRN complex.
Boster reagents
SLPI Western Blot Antibodies
Catalog antibodies with Western blot application and product-specific WB images. Evaluate suitability with the reported sample, controls and experimental conditions.
Real WB data
Anti-Antileukoproteinase SLPI Antibody
Cat # A01682
The catalog reports A01682, an anti-SLPI antibody with stated human and mouse reactivity. Its Western blot image shows Daudi cell lysate tested at 1 and 2 μg/mL; this example does not establish performance across other samples.
Which to pick: A01682 is the only listed option. Its Daudi lysate Western blot image provides a starting reference for testing SLPI; confirm performance in your own sample and conditions.
Source: BosterBio SLPI gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P03973.
- Human Protein Atlas. SLPI tissue expression.
- PMC4423143 — target-verified WB comparison
- PMC2836917 — target-verified WB comparison
- PMC2193830 — target-verified WB comparison